The visual pigments of man are formed by the interaction of a polyene chromophore, II-cis-retinal I, and a protein moiety termed opsin. All other known animal visual pigments have the same general structure and have either II-cis-retinal I or II-cis-3-dehydroretinal 2 as their chromophore. The absorption and activation spectra of visual pigments show a wide range of lambda max values, and abnormal human vision has been correlated with abnormalities or absence of retinal visual pigments. Visual pigments formed with but a single chromophore (e.g. II-cis-retinal 1) may vary greatly in spectral sensitivity, and it is generally accepted that the opsin determines the lambda max of the visual pigment. It appears that the fine structure of the opsin chromophore binding site defines the spectral characteristics of the visual pigment. This infers that different visual pigment opsins vary in primary structure. We propose to define and compare the primary structure of visual pigment proteins from different species, which display the same or different lambda max, in order that regions of sequence conservation and sequence variation may be identified which are important for visual pigment spectral sensitivity or visual pigment physiology. Initial comparative studies will concentrate on the amino acid sequences adjacent to functionally active groups (e.g. the photo-exposed sulfhydryl group). OBJECTIVE: a. Overall objective of the project: The visual pigments of man and other animals display a wide range of spectral sensitivities which are of significance for perception under varying conditions of illumination. The lambda max values for visual pigments formed with II-cis-retinal extend from 432nm to 57 nm. The distinct spectral characteristics of the three different cone visual pigments of man are responsible for color vision, and it appears that alterations of the visual pigment protein moiety may lead to abnormal vision. The opsin protein of the visual pigment appears to have a major role in determining the spectral and physiologic characteristics of the native visual pigment. However, only very limited information is available concerning the primary structure of the opsins. The immediate objective of the presently proposed research is to study and define the primary structure of the protein moiety of bovine rhodopsin. The long-term goal of these inestigatio (Text Truncated - Exceeds Capacity)